Python int() usage and examples

Python built-in functions

The int() method returns an integer object from any number or string.

The syntax of the int() method is:

int(x=0, base=10)

int() parameters

The int() method takes two parameters:

• x-The number or string to be converted to an integer object.
  default parameteris zero.

• base-in xthe base of the number.
  It can be 0 (code literal) or2-36.

The return value of int()

The int() method returns:

• Given a number or an integer object in a string, the default base is considered as10

• (Without parameters) Returns 0

• （If a base is specified）then the specified base (0,}2,8,10,16）Handling strings

Example1How int() works in Python?

# Integer
print('int(123) is:123))
# Float
print('int(123int(23) is:123int(23))
# String
print('int('123) is:123))

When running the program, the output is:

)) is:123.　123
)) is:123int(23.　123
) is:123　123

Example2

1010, int is:1010,　2))
1010, int is:1010,　2))
# Octal 0o or 0O
12, int is:12,　8))
12, int is:12,　8))
# Hexadecimal
print('For A, int is:', int('A',　16))
print('For 0xA, int is:', int('0xA',　16))

When running the program, the output is:

For1010, int is:　10
For 0b1010, int is:　10
For12, int is:　10
For 0o12, int is:　10
For A, int is:　10
For 0xA, int is:　10

Example3Custom object int()

Internally, the int() method calls the __int__() method of the object.

Therefore, even if an object is not a number, it can be converted to an integer object.

You can return numbers by overriding the __index__() and __int__() methods of the class.

These two methods should return the same value because old versions of Python used __int__() and newer Python uses __index__() method.

class Person:
　　　　age =　23
　　　　def __index__(self):
　　　　　　　　return self.age
　　　　
　　　　def __int__(self):
　　　　　　　　return self.age
person = Person()
print('int(person) is:', int(person))

When running the program, the output is:

int(person) is:　23

Python built-in functions